Place oven rack in middle position and heat oven to 325 degrees. Grease and flour 16-cup tube pan. Pulse fruit in food processor until finely ground, about 5 pulses. Combine flour, baking powder, and salt in bowl. Using stand mixer fitted with whisk, whip sugar and eggs on medium-high speed until pale and thick, about 3 minutes. Decrease speed to low and slowly add butter until incorporated. Add processed fruit and flour mixture until just combined. Scrape into prepared pan and smooth top. Bake until toothpick inserted in center comes out clean, about 1 hour. Let cake cool in pan on wire rack for 25 minutes. Remove cake from pan and let cool completely.
Transfer cooled cake to serving platter. Spread whipped cream evenly over cake.